Topical therapeutic compositions have been traditionally used for pain relief of muscles, joints, as well as skin irritation and inflammation. In recent years, other types of pain, such as headache, have been treated using traditional topical active ingredients such as menthol. These types of products have been available as dial-on stick and cream types of dosage forms for application to the head, even though menthol is traditionally associated with topical treatment of muscle and joint pain. These types of treatments speak to the fact that pain experiences are extremely varied in the human population, and the sources, mechanisms and treatments are not completely understood by the medical profession and consumers of pain medications.
The use of topical therapeutic products can be improved through the use of occlusion of the product or active ingredient on the surface of the skin. In this case, occlusion has several advantages including the sealing of volatile components, prevention from having a topical therapeutic composition from rubbing off on surfaces such as clothes, as well as in the sealing of ingredients that emit unpleasant odors from the topical therapeutic composition. The occlusion of topical therapeutic compositions can also be utilized to facilitate delivery of the topical ingredient by having a consistent applied pressure of the topical ingredient through the epithelial layer of the skin. Occlusion, for instance by coating of the topical therapeutic composition applied to the skin by an adhesive patch, might also enhance the action of the active ingredients due to increase in skin permeability under the adhesive patch. Various means may be utilized in order to facilitate occlusion on the skin surface; including the addition of bandages, fabrics, hydrophobic liquid layers, tapes, impregnation of a topical into a patch.
Sprayed fabrics are a recently developed technology and enable the spraying of fibrous materials on the surface of an individual's body or onto a substrate, forming semi-permanent layers of fabric-like coatings. These are generally referred to as non-woven types of materials, such as shown in published U.S. Patent Application No. 2005/0222320 which comprises a sprayed fabric comprised of fibers, a binder and diluent. Spray fabrics may include ingredients that possess therapeutic or sensitizing properties; such as topical heating or warming agents. When such an agent is embedded in the composition of the sprayed fabric, it is trapped in its matrix structure and limits its availability for delivery on the surface of the skin, or subsequent absorption through the skin to underlying tissues. In addition, if an agent is impregnated into the sprayed fabric, it must be compatible with sprayed composition (i.e., the polymers, fibers, diluents, propellant and binders) in order to prevent degradation of the active ingredient of the functionality of the fabric. If the active ingredient is impregnated into the fabric, there is no real occlusion of the active ingredient upon delivery which can also lead to the potential for rubbing off on clothes, surfaces and emission of unpleasant odors.
Dual liquid delivery devices have been described in the art for delivering a variety of liquids, including the simultaneous delivery of multiple liquids. In U.S. Pat. No. 4,969,579, two liquids are combined upon simultaneous release from a dual chamber canister. In U.S. Pat. No. 5,535,950, teaches that a single trigger can be used to deliver two liquids from side-by-side pump pistons.
Many traditional topical pain relief compositions rely on one or more counter-irritants as the active ingredient. Counter-irritants function by providing a cold, hot, tingling, or other sensation that is believed to interfere with transmission of a pain signal to the brain, providing temporary lessening of the perception of sore muscles or aching joints. For example, Ben Gay Ultra Strength pain relieving cream contains such counter-irritant active ingredients as menthol (10%), camphor (4%), and methyl salicylate (30%), and has an onset of sensation within about 3 minutes with about a 90-minute duration of sensation.
Cooling agents have been disclosed in the prior art for use as sensates, such as disclosed in U.S. Pat. No. 7,189,760, wherein a substantially pure compound and method of preparing an ethyl ester of N-[[5-methyl-2-(1-methylethyl)cyclohexyl]carbonyl]glycine is shown. This material is described as having substantially high physiological cooling activity.
Similarly, U.S. Pat. No. 7,030,273 discloses additional cooling agents. In this patent, N-alkoxyalkyl substituted-2,3-dimethyl-2-isopropylbutyramides compounds are demonstrated to have physiologic cooling effects.
The invention described herein improves the delivery of a topical therapeutic agent and avoids incompatibility issues associated with fiber impregnation.